LowLevelAPIEmailService has optin and optout implemented.
Merge branch 'master' of git@github.com:novaksolutions/infusionsoft-php-sdk.git
Infusionsoft App for Testing now implements getHostname correctly.
AppPool::setApp now does a strtolower on the hostname before adding it.

Previously getApp did a strtolower, but setApp did not.  So as long as you were always using all lowercase hostnames, you were fine.